Question about 1996 Mitsubishi Galant

1 Answer

Idle Air Control/Check Engine Light

My car has slowly been consuming more gas. Recently the check engine light came on. I took it to the street mechanic close by and he tested it on the dash. Gave code P0505. He doesn't know what the hell the Idle Air Control System is, and he wanted me to replace the whole electronics for $500 even though it was getting power. I read up and I don't seem to have the symptoms with my car when it's in idle that most people do. It idles fine. Only uses a LOT of gas now. Could there be another problem with it? 1996 Mitsubishi Galant S

Posted by on

  • Dan Todd May 11, 2010

    An idle air control valve system will run about $250 for your engine.

    But if you aren't experiencing idle symptoms, erratic, not fast when it is cold, then the code might not have been correct.

    In my opinion the wrong way to diagnose a problem is to start throwing parts at it until it's fixed. I assume by now he cleared the code out and perhaps you are not getting the check engine light. But if you do, I would take it to a dealer and have them check it out.

    The analysis will cost you, but then you might go somewhere else or buy the parts and do it yourself if mechanically inclined.

    If you run across another street mechanic who "doesn't know what the hell an air cobtrol system is", run, don't walk away from there.




1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 232 Answers

There are a lot of sensors that help the computer adjust the idle. Any one of them could be at fault. You'll have to take your car to get diagnosed. Mechanics are good at guessing and replacing things at random. Have it diagnosed and find out what needs to be changed for sure. What you can do is check for vacuum leaks. Try to remember if any work was done and where check around the area for loose, cracked or disconnected vacuum hoses. Also check for striped, disconnect cables or wires etc. Any air coming in after the mass air flow sensor will throw the computer off. Yea don't replace anything at all without knowing its the cause. Give it a tune-up replace the air filter, ignition components, fuel filter and pressure regulator also the engine oil and filter. This is the cheapest way and it could get it fixed! Plus you got to do it any ways. After the tune-up restart the computer, disconnect the negative or ground cable from the battery. Wait five minutes then reconnect, this is an important step. The computer will now set for the new air filter, ignition etc. and adjust the idle accordingly. If the check engine comes back on then you have a problem that goes beyond this. Then you'll know you have to have it diagnosed for sure.

Posted on May 14, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

2006 saturn vue rough idle

Look at tube from air cleaner filter back to the engine ,make sure there are no splits in the intake tube , air getting past the mass air sensor sends bad signals to the ecm.

Nov 04, 2016 | 2006 Saturn Vue

1 Answer

In gear idle tries to go up to around 4000rpm without stepping on the gas, won't idle down till I step on brakes, way slow acceleration, Traction control off light is on, check engine light on

Something could be wrong withthe idle circuit or air cleaner not installed properly. Need to check engine code first,also heck for vacum leak listen for air escapeing.

Dec 04, 2015 | 2006 Chevrolet Malibu LT

2 Answers

What can cause a Fast idle on 1999 Ford Escort?

Try cleaning the throttle body and check the gap on all the spark plugs also all electrical sensor plugs and battery terminals this could be related to engine temperature also if to hot rpms stay up longer to cool off but maybe your idle air control valve is bad when did it start?

Feb 09, 2018 | 1995 Ford Escort

2 Answers

My 2006 Chevy Silverado 1500 5.3 L engine surges +/- 200 rpm between 30-59 mph in final drive lower gears runs fine. No check engine light or computer code generated until recently which showed...

a bank 1 or a bank 2 generally means an 02 sensors bad. or you may simply have a faulty gas cap. i would try the gas cap 1st,make sure it's tight, the engine running for a few minutes,then cut engine off. then open gas cap,do you hear pressure [air] releasing from the fuel tank? ok if not that,then if bank 2 is really bad,your check engine light would be on. but if the idle control sensor is bad,no light would be on at all. and it[engine] would idle up and down.or would'nt idle at all,or would idle up and down,just like what you've described. good luck and thank you for choosing and please let me know if i'ved assisted you!

Feb 20, 2011 | 2006 Chevrolet Silverado 1500 2WD

1 Answer

Car wont stay on you let go of the gas and it dies

Check the idle air control valve its right on the front of the throttle body it may be stuck closed and not allowing air to bypass the throttle plate to allow the engine to idle, do you have a check engine light on at all, there could be a number of sensors that could have a problem not allowing the engine to idle when the throttle plate is closed like the idle air control valve, throttle position sensor......

Dec 07, 2010 | 1993 Subaru Loyale

3 Answers

Would an idle control valve cause a car not to accelerate?

no, idle air control valve is literally to control your idle speed.
what happen when you press on gas? car shakes, RPM goes up, or engine just bogs down?

Mar 09, 2010 | 2004 Infiniti I35

2 Answers

2003 MR2 will not idle

Possible throttle control motor failure. Possible Idle Air Control Valve failure.
Is the "Check Engine" light on? Hard to determine without more info. Sorry.

Sep 14, 2008 | 2003 Toyota MR2 Spyder

Not finding what you are looking for?
1996 Mitsubishi Galant Logo

378 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mitsubishi Experts


Level 3 Expert

79865 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8836 Answers

Are you a Mitsubishi Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides